There is known a technology that detects an anomaly in an in-vehicle unit and notifies a center of the anomaly. For example, Patent Literature 1 discloses the technology that uses a shock sensor included in an in-vehicle unit to detect an anomaly in the in-vehicle unit and notifies a center of the anomaly.
Moreover, there is known a system in which an in-vehicle unit wirelessly communicates with an in-vehicle unit of another vehicle or a roadside instrument and thereby provides a driver of a unit-mounted vehicle (also referred to as a host vehicle) with various services (hereinafter referred to as in-vehicle communication services). There is known an example system in which the in-vehicle unit measures a host vehicle position using a positioning instrument of a satellite positioning system included in the in-vehicle unit itself, transmits information including the host vehicle position to an in-vehicle unit of another vehicle or a roadside instrument, and thereby provides a driver of the host vehicle with an in-vehicle communication service corresponding to the host vehicle position.